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Date: Thu, 5 Aug 2004 15:04:22 +1000
From: Tim Robbins <tjr@freebsd.org>
To: freebsd-current@freebsd.org
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Subject: Atomic operations on i386/amd64
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Is there any particular reason why atomic_load_acq_*() and
atomic_store_rel_*() are implemented with CMPXCHG and XCHG instead of
MOV on i386/amd64 UP?

Also, could we use MFENCE/LFENCE/SFENCE in combination with MOV on
SMP systems instead of LOCK CMPXCHG / (implied LOCK) XCHG?


Tim